CVE-2026-31602: Linux kernel · ALSA: ctxfi: Limit PTP to a single page
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 12 Nov 2026, 03:32 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
AI-suggested
A fix has been applied by reverting CT_PTP_NUM to 1 in the Linux kernel source, preventing the out-of-bounds memory access. Users should update to the fixed Linux kernel version containing this patch once available. No additional mitigations are indicated by the vendor.
Description
CVE-2026-31602 is a vulnerability in the Linux kernel ALSA ctxfi driver where the number of page table pages (PTP) was incorrectly increased from 1 to 4, causing out-of-bounds memory access and page faults. This occurs because the driver always uses PTEs from a single PTP page, but the code attempts to access beyond the allocated space when multiple pages are assumed. The issue was fixed by reverting the PTP count back to 1, preventing invalid memory access.
References
- git.kernel.org/stable/c/c5908160e17cb56e1f61fbaee08adc21083f4933 (opens in a new tab)
- git.kernel.org/stable/c/de8016fb0904d68ac886e375069535996baa42ee (opens in a new tab)
- git.kernel.org/stable/c/2b4331c08c0b385598b4d8ccd71e93ab3f4b2578 (opens in a new tab)
- git.kernel.org/stable/c/452894005b4abe141b11fe01e7bfe152e6d3860f (opens in a new tab)
- git.kernel.org/stable/c/365c36e1a126c6aa1aecedd3a351bcabc66f0c29 (opens in a new tab)
- git.kernel.org/stable/c/3fd0685d7fef68c2d8a04876bcf9eaa0724ad6a5 (opens in a new tab)
- git.kernel.org/stable/c/b7f5ecd13cce8c2f8fa5a84c9aab65997142577e (opens in a new tab)
- git.kernel.org/stable/c/ad9011a795407093dcf507f6e5da1828987b4b47 (opens in a new tab)
- git.kernel.org/stable/c/e9418da50d9e5c496c22fe392e4ad74c038a94eb (opens in a new tab)